3) We are group of 10. We plan to start the hike by 12:30am. Does it seem reasonable time to start? We are estimating 1mile per hr, so it would take 11-12hrs to reach summit. Is this good estimate, over estimate?
A lot of people...10?
Be sure the leader is also the sweeper on the descent. Be sure those who cannot make the ascent, know their way back down and leave a note on the leader's vehicle that they left the trail safely. Leave no one behind or account for all before leaving the trail head after the hike.
1 mph is an excellent pace, but you can probably do 2 mph up and down. Pace is the key. The most difficult is from Trail Crest to the summit. Because you can see the summit 2.5 miles away.
1230 am is a good start. The key is getting the others to be ready by 1230 am. I like to start at that time to get to the summit early and come back down before the others.
Weather: Monsoonals are usually July and August. September iffy can happen. Beware of puffy clouds. Convection can turn those clouds into cumulonimbus (anvilheads). The wind can be very cold coming down over the crest as you make your way to Trail Camp. Dress in layers. Start warm, stay warm.
If you are coming from Dublin, you can stop at Tuolumne Meadows to acclimatize and venture around or hike up Lembert Dome. Mammoth is off the beaten path but is an option. Bring money to shop and eat. Horseshoe Meadows is a very good alternative. Make it a picnic and enjoy the scenery. Mossies may be a buzzin so take bug spray.
